Together, Mark and David traveled 570 miles to the beach. If Mark traveled 255 miles, how far did David travel?

If Mark traveled 255 miles, and together they traveled 570 miles, than David traveled 570 miles - 255 miles = <<570-255=315>>315 miles. Answer: \boxed{315}.

To find out how far David traveled, we need to subtract the distance Mark traveled from the total distance they traveled.

Total distance traveled - Distance Mark traveled = Distance David traveled

570 miles - 255 miles = Distance David traveled

Therefore, David traveled 315 miles.

To find out how far David traveled, we can subtract the distance traveled by Mark from the total distance.

Total distance = 570 miles
Distance traveled by Mark = 255 miles

To find the distance traveled by David, we subtract Mark's distance from the total distance:

Distance traveled by David = Total distance - Distance traveled by Mark
Distance traveled by David = 570 miles - 255 miles

Calculating this gives us:

Distance traveled by David = 315 miles

Therefore, David traveled 315 miles.